It has long been desired to grow biaxially oriented oxide buffer layers other than CeO.sub.2 directly on textured-Ni substrates. Also it has been desired to provide an alternative to pulsed laser deposition processes that may be easier to scale up for producing thick buffer layers.
Recent developments in deposited conductors, both rolling assisted biaxially textured substrates (RABiTS), and ion-beam assisted deposition (IBAD) based on YBa.sub.2 Cu.sub.3 O.sub.7 superconductors are promising, especially superconductors deposited on buffered substrates.
The "deposited conductor" approach described herein is useful for growing superconductors such as REBa.sub.2 Cu.sub.3 O.sub.7, (Bi,Pb).sub.2 Sr.sub.2 Ca.sub.n-1 Cu.sub.n O.sub.2n+4 (n=1-3), Tl.sub.1 Ba.sub.2 Ca.sub.n-1 Cu.sub.n O.sub.2n+3 (n=1-4), Tl.sub.2 Ba.sub.2 Ca.sub.n-1 Cu.sub.n O.sub.2n+4 (n=1-3), and Hg.sub.1 Ba.sub.2 Ca.sub.n-1 Cu.sub.n O.sub.2n+2+.delta. (n=1-4) with high critical-current densities. These high J.sub.c conductors will be suitable for transmission lines and various other applications.
This invention opens up a wide variety of possibilities of growing several other buffer layers such as SrTiO.sub.3, LaAlO.sub.3, REAlO.sub.3 (RE=Rare Earth), BaZrO.sub.3, and CaZrO.sub.3 on either buffered-rolled metal substrates or directly on rolled metal substrates. The demonstrated buffer layers may also be useful for photovoltaics, ferroelectrics, sensors, and electro-optic applications
The following sections of publications also relate to the present invention, and are hereby incorporated by reference:
X. D. Wu, S. R. Foltyn, P. Arendt, J. Townsend, C. Adams, I. H. Campbell, P. Tiwari, Y. Coulter, and D. E. Peterson, Appl. Phys. Lett. 65 (15), 10 Oct. 1994, p1961. PA1 M. Paranthaman et al., Physica C 275 (1997) 266-272. PA1 C. Prouteau, J. F. Hamet, B. Mercery, M. Hervieu, B. Raveau, D. Robbes, L. Coudrier, and G. Ben, "Significant improvement of superconductivity of laser ablated YBa2Cu.sub.3 O.sub.7 /MgO" thin films: Introduction of a SrTiO.sub.3 buffer layer," Physica C, Vol. 248, 108-118 (1995) Chunyan Tian, Yang Du, and Siu-Wai Chan: "Epitaxial formation and characterization of CeO.sub.2 films." MRS proceeding Vol 355 on Evolution of Thin Film and Surface Structure and Morphology edited by B. G. Demczyk, E. D. Williams, E. Garfunkel, B. M. Clemens, J. J. Cuomo, 1995. ISDN: 155899-256-1. PA1 Wei-Yung Hsu, and Rishi Raj: "MgO epitaxial thin films on (100) GaAs as a substrate for the growth of oriented PbTiO.sub.3," Appl. Phys. Lett., Vol. 60, June 1992, pp.3105-3107.